AC Repair

Rob,
What's your thoughts on the comment that every unit needs a recharge at some point? Does the refrigerant lose its cooling ability over time and if so what is that time for say a house, boat, car, etc?
Thanks.
 
Morning Guys

Thanks for all the advice and help!

Rob
after removing the filter I tried vacuuming the front of AC unit to remove all dirt in the fins but i did notice when i used the "Fin Comb" to straighten out any bent fins there was still dirt in fins..

How do i clean out fins thoroughly?

can i use one of those deep cleaning steam machines that you clean your bathrooms with?

Walter
I'm going to try all of the above if all fails ill have to spend the $$ and buy a new unit..
I will say when the unit is defrosted it works great until it ices up again..

tomust

I might just give Alven a call as well

Again
Thanks again for all your help..
 
quote:
Originally posted by CAPTINMB

when i used the "Fin Comb" to straighten out any bent fins there was still dirt in fins..

How do i clean out fins thoroughly?

can i use one of those deep cleaning steam machines that you clean your bathrooms with
I will say when the unit is defrosted it works great until it ices up again..
Click to expand...


This leads me to believe your problem could well be only a dirty (some techs call it "dirt fouled") Evaporator Coil.

Can you get at both faces of that cooling/evaporator coil? If you can, spray it with "coil cleaner"

41UV9GcvEsL._AA160_.jpg


And if you can, hose it clean. You'll get LOTS of "buggers" out of it. Best to spray water OPPOSITE the air flow direction.

I can't hose our home unit, so I fill a sprayer with water and pump it as hard as it'll go. That lets me rinse the coil fins with a volume of water that I can trap and wipe up.
41sJn1H16nL._AA160_.jpg


Both of above are only examples from Amazon. The last cleaner I bought was in a spray bottle vs. spray can and came from a big box or hardware store, forget which. "Lundmark's Coil Cleen." You can use 409/Simple Green if you rinse well. One of the pluses to coil cleaner is it isn't supposed to be corrosive on that delicate aluminum and copper the coils are made of.

A Pressure Washer is too much. You'll flatten the fins.
 
I never recharged any of my three units in 15 years. If it alit broke don't fix it.

IMO recharging is a temporary fix to a hidden leak that wont fix itself.
 
It doesn't hurt to have someone put a manifold on an older system to see the state of charge. No, it doesn't go "bad", but minor leaks do occur. Schrader valves leak sometimes as do other parts of the system.
 
A friend owns a HVAC company. His words not mine. "It is a 100% closed system and should never loose the freon. If it needs freon, it has a leak. It can be such a small leak that addiing freon could last many months. So you can buy a season by getting it filled with the freon. No guarantees how long it will last, but it will leak. I personally kept my AC going for 2 years by getting freon added once per season in the spring and it lasted all summer. Then the compressor started tripping the breaker and I replaced the entire unit on my own. As Walter stated earlier, it is an easy DIY and I have a good contact that got me the unit very quickly. It works much, much, much better than the old one.
 
A properly installed ac system should never ever need freon.

YEs putting gauges on is a bad thing. These small systems only have onces of refrigerant . Every time u disconnect u loose gas. U mess up and u now created a problem.

OBSERVATION is the best tool anyone could have . A temp gun is 2nd .

Leak detectors on a water cooled unit are useless. 90 % of the time the failure is in the condensor .

other 10% its the service fittings.

Rob
 
If cleaning doesn't work the icing up also points to low refrigerant. Here's a cheap and easy test:

With your system thawed out, use an IR or air conditioning thermometer to measure temperatures at your return and at the closest vent (be sure to allow the system to warm up for a good 10-15 minutes before doing this). The difference between the two should be between 14 and 19 degrees Fahrenheit. Anything much outside of that range and there's likely an issue that will require service.
 
^^^what Kurt said^^^ If the refrigerant charge is low, the liquid from the compressor expands more rapidly with a low charge. Correct charge creates expansion throughout the evaporator coil. Low charge expands right at the entry point and can drive the coil's temperature below freezing there. Frost develops, freezes to ice, more expansion, more frost, more ice. Spreads across the coil since the ice acts as an insulator. A unit that is BOTH Dirty and Low will freeze more easily than one that's Dirty OR Low. Air flow helps offset all this, so keeping the system off low fan speeds also helps.
 
Mike,
Follow Rob's lead on what to do, he is an expert in his field, which happens to be this field:). I was in this field as a summer temp for General Electric while in college. That was many moons ago and then, we were referred to as "Shake and Bake Techs" so although I get the workings, not an expert.

Walter
 
quote:
Originally posted by Robski97

YEs putting gauges on is a bad thing. These small systems only have onces of refrigerant . Every time u disconnect u loose gas. U mess up and u now created a problem.

Click to expand...


I only meant having a trained, licensed tech do it. Why else are there manifolds? Every darn system I own needs a charge from time to time. 30 year old HVAC unit at my office. Both autos. 15 year old system at my house. Even the 3 A/C units on my boat (not to mention my refrigeration, although that's R134a). I don't doubt you that in an ideal world these systems should never need a charge, but I find the world well less than ideal (or I just have horrible luck, which is entirely possible).
 
Hi Guys

Update..

Went to Boat on Wed... AC was running full for three days. No Ice and the cabin was a cool 70 degrees.

The only thing i did different when i closed up boat on Sunday was i left the cushion off the seat where the unit is ( its located under one of my seats)

My thoughts were if i kept off the cushion the unit might get more air..

Im going back tonight ill see how it looks.

I think (and hope) it just needs a good cleaning
 
Air flow is always the first step before panicking. Great news - congrats.
 
Kurt,
Im thinking u have really bad luck .

Even professional tech makes a mistake and excessive freon loss can happen. Again our lil ac unit only holds a pound of refrigerant.

I have never needed to add gas to any system on my boat . ( i have but thats me doing something u shouldnt )

My house nope, my office nope.

So yea bad luck pal.Sorry .

Rob

AS for the orignal post... Glad it was figured out. Air flow ( dirty filter, Obstruction being clothes Soda cases etc) is not unusual. We always end of up blocking the cockpit ac with soda cases when we go away on long trips . They stack nicely in front of the evaporator .
 
You must log in or register to reply here.
Back
Top